The present invention relates to the solidification or crystallization of fats and fat-containing foods, using a magnetic field.
Fats are widely used in solid or crystalline form in food products. The properties of the foodstuff depends, in part, on which form of fat is solidified or crystallized. Certain fats are polymorphic, i.e., they are capable of solidifying in more than one crystalline form, and the crystal forms may have important effects on the properties of the foodstuff. For example, cocoa butter is polymorphic and six crystal forms have been described (See Talbot in Industrial Chocolate Manufacture and Use (Ed. Beckett), 1994, Chapter 11). Form V is desirable for processed chocolate since this form of cocoa butter gives chocolate snap, texture and gloss. With time, however, form V converts to form VI, which is responsible for the white sheen which may appear on chocolate known as bloom.
WO 98/30108 discloses methods for making chocolate that minimize increases in viscosity associated with tempered chocolate. The method involves adding a seeding agent to molten chocolate and, according to one embodiment, this seeding agent can contain significant amounts of the form VI polymorph on an industrial scale and most of the industry use continuous scraped surface heat exchangers (See Nelson in Industrial Chocolate Manufacture and Use (Ed. Beckett), 1994, Chapter 12), which machines are relatively complex and require critical temperature control processing of fats and fat-containing foods.
Thus, there is a need for improved processing of fats for use in chocolate products.
The present invention provides a process for controlling the solidification or crystallization of a fat which comprises applying a magnetic field to the fat at a field strength that is sufficient to promote solidification or crystallization of that fat.
The magnetic field, of the present invention, has a strength of between 220 and 700 Gauss and is produced by a permanent magnet, an electromagnet, or is a radio frequency generated or pulsed magnetic field. It may be applied to the fat or a fat containing food during solidification or crystallization or, instead, may be applied prior to the completion of crystallization when the fat is partially set or is liquid.
Advantages of the present invention include increasing the rate of setting time of the fat and increasing the shelf life of the fat or a fat containing food. Additionally, the process of the present invention produces the fat in one or more stable forms.
The present invention is also provides a process for directly producing cocoa butter in form V or form VI which comprises applying a magnetic field to a liquid phase of cocoa butter at a field strength sufficient to produce form V or form VI cocoa butter.
The magnetic field may be applied to partially set cocoa butter prior to completion of crystallization or instead may be applied to the cocoa butter during solidification or crystallization of liquid cocoa butter. This process increases the setting time of cocoa butter up to 40%.
The cocoa butter of the present invention may be included in a chocolate and the process of applying the magnetic field to the cocoa butter increases the shelf life of the cocoa containing product, i.e., chocolate. Thus, the present invention discloses a cocoa butter containing product in solid form wherein the cocoa butter is formed directly from a liquid phase in crystal form VI without passing through another crystal form.
The present invention is also directed to a method for reducing bloom on chocolate products which comprises converting at least a portion of form V cocoa butter in the chocolate to form VI cocoa butter during production of the chocolate so that bloom resulting from the conversion of form V cocoa butter to form VI cocoa butter in the chocolate after production is reduced.